Pneumatic-despatch-tube system.



Patented Nov. 9,

A. WATSON.

PNEUMATIC nEsPATcH TUBE SYSTEM.

APPLICATION FILED JULYZT, I9I4.

Si Va @@ameg.

COLUMBIA PLANCGRAPH C0WASHINGTON. Dv C.

UNITED STATES-PATENT Ol'dlCE.v

ALEXANDER WATSON, or Bancarioim?,A MASSACHUSETTS, Assrenon or ONE-HALF To l WILLIAM G. MITCHELL, OF MATDEN, :MASSACHUSETTS :PNnMATIc-DEsPATcH-TUBE SYSTEM.

Application led July 27, 1914. Serial No. 853,258.

To all whom t may concern.' Y

Be it known that I, ALEXANDER WATSON, a citizen o the United States, and resident of Beachmont, in the county of Suffolk and State of Massachusetts, have invented new and useful improvements in Pneumatic- Despatch-Tube Systems, of which'Y the vfollowing is a speciiication.

This invention relates to pneiunatic despatch tube systems of the type wherein the despatch tube normally contains atmospheric pressure only and the transmission of the carrier is effected by the introduction of compressed air into vsaid despatch tube.

T he principal objectr ofthe invention is to provide e'licient means for the introduction of a flow of Compressed airfinto the despatch tube and for automatically shutting ofi such iiow as soon as a sufficient volume of compressed air has been introduced to eliect the transmission oi the carrier.y

Referring to the drawings which illustrate an embodiment of my inventiom-Figure l is a vertical sectional view partly in elevation of an air supplyvv valve and its associated operating devices and pipe connections; Fig. 2 is a section on line 2 2 of Fig. l; and Fig. 3 is a detail sectional view partly in elevation showing the supply valve in open position.

rl`he terminal consists cylindrical portions A, .A, with a hollow connecting portion A2. lVithin said casing A" is a cylindrical partition or wall A3 having diametrically opposed, radially extending branches A, preferably formed integral with said partition and said casing (Fig. 2l, said partition and branches dividing said casing A into an inner or working chamber X and an outer chamber having two independent compartments Y'and Y. The partition or wall AS is provided with an inlet port a. from said compartment Y to said chamber X and is also provided with an outlet port c from said chamber to said compartment Y. The compressed air s'upply pipeV B is suitably secured to the lower end ot' said casing A and` said casing is open at said end to permit the continuous passage of air from said pipe into said compartment Y and said chamber X. Vithin said working chamber X. and located between said ports is a. valve seat A5 for the air supply control valve C, which has ahollow stem, at the top of which is a piston C2 having a port c open at alltimes orthe pasvSpec'zic'ation of Letters Patent.

of a casing havingv Patented NOV. 9,

sage of air therethrough, the size of said l port being regulated by a plate c3 movably secured on said piston. A disk of leather or the like, c', secured to said piston by a plate c, insures the air-tight fit of said piston within said cylindrical working chamber. The top of said partition or wall A3 is internally screw-threaded to receive a cap D in which is slidably mounted a push rod E, hollow throughout a portion of its length and open at its lower end, said rod extending into and in sliding engagement with said valve stem C. Said rod has a head G which normally projects above said cap yD and is further provided with an enlargement or disk ij forming a valve preferably formed integral therewith and having a iange c in which is a packing c of rubber or other suitable material. When the parts are in their normal position shown in liig. l, the spring F surrounding ysaid push rod E and held between the head G and a shoulder (Z2 on the cap D, holds said valve E tightly against the valve seat (Z upon the under side of the cap D. At a point between said valve and said valve seat, the push rod .E is provided with ports e2, communicating with the hollow portion of said rod and having a combined area greater than the area of the port c of the piston C2.

The cylindrical casing A, whichis connected'with the casing Aby the hollow portion A2, is open at its top and supports the despatch tube H having the'usual apertures /L for the passage of compressed airinto said despatch tube to effect the transmission of the carrier. Said-casing A is further provided with a laterally extending cylindrical chamber A communicating with said despatch tube by a. port 7L', in which is a1 piston J provided with a piston rod J which projects through the capa2 which closes one end of said chamber. A spring K surrounds said rodvJ and is held between said piston J and said cap a2. The latch L pivoted on the lug A7 on said casing A, is provided with a slotZ at its end through which .the projecting end of ythe piston rod J. passes, and said latch is suitably secured to said rod as by nuts J2, thek rod J being screwthreaded to receive said nuts.

Upon said terminal are brackets Mcarrying a pin N to which is pivoted by the arms O, the' despatch tube cover O, which is provided with a catch 02 adapted .to coperate with said latch L to lock said cover in closed position. A. post extends through said cover and has at its lower end a disk l of smaller diameter than that of the mouth of said despatch tube and which serves to hold a packing of rubber or the like between the top of said cover and said disk. Between said arms O is a pin Q, on which is pivoted a lever or handle lt having a. recess FX, through which the post .F passes. urrouinling said post F and held between the top wall of said recess llt and the cover (l is a spring S, and there is an adjusting nut P2 on the top of the post l) which is screw-threaded to receivek it. YLlpon said pin X and between said arms O there is pivotally secured an arm T, one end of which rests upon the head (l of the push rod E, the opposite end of said arm 'l being adapted to be engaged by said handle l for the purpose presently to be described Normally the parts are in the position shown in Fig. l, the valve C being held on its seat, and the despatch tube cover G being held by the spring l in the open position shown in said figure. After inserting the carrier in the despatch tube in the usual way, the user grasps the handle l and swings said handle and its associated parts downward into the dotted line position shown in Fig. l, thus seating the cover O and closing the despatch tube. r'he handle R is then swung downward upon its pivot Q, compressing the spring S and causing the free end of said handle to engage and lift the arm T so that the end of said arm resting on the head G of the rod E, moves downward and pushes down the said rod. The handle R is then released, whereupon the spring S returns it to the dotted line position shown in Fig. l, andthe spring F returns the push rod E to its normal position shown in said ligure. lt will be understood that the above described operations of closing the cover D, pushing down the rod E and permitting it to return to normal position, are in effect a single operation very quickly performed, the user swinging the handle R on its pivot Q. at the instant of seating said cover and immediately releasing it at the end of its downward stroke so that the spring F is free to return the rod E to normal position. lllhen said rod E is pushed down in the manner just described, it slides in the valve stein C and the enlargement or disk E with its packing e is moved away from the projection (Z on the under side of the cap D, permitting the compressed air confined in the working chamber' between said cap and said piston C2 to flow through the ports e2 in the hollow rod E and escape through the open end of said rod. It will be clear that the said piston being thus relieved of air pressure upon its upper surface will be immediatelyT forced upward by the pressure of air in the working chamber4 upon its. lower surface, thus lifting and unseating the valve t) to which it is secured through the valve stem C. Fig. 3 shows the position of the parts at the instant immediately following the depression of the rod E and before the spring F has returned said rod to its normal position.

Vhen the valve C has been opened `in the manner just described, the compressed air flowing through the outlet a", chamber Y, casings A2 and A, and ports i1., into the despatch tube H, enters the port ,/L, and pushes the piston .l outward, thus causing the latch L secured to the piston rod J to engage the catch O of the cover O, locking said cover upon said despatch tube.

During the transit of the carrier to its destination, the compressed air slowly flows through the port o of the piston C2 until the air pressure above said piston is sufficient to overcome the pressure below it, whereupon the piston moves slowly downward, returning the valve C to its seat and cutting olf the air supply from the despatch tube il. As soon as the air supply is thus shut on', the pressure is removed from the piston J so that the spring K .returns it to normal position, thus drawing back the latch L, and unlocking the cover O which is returned to normal open position by the spring lV. It will be understood that the size of the port o' of the piston C2 is regulated by the plate c3 so that the air is admitted therethrough in such volume as will cause the piston to move downward and close the valve at a predetermined interval of time, z'. e. the interval of time necessary for the carrier to travel from the sending end to the delivery end of the despatch tube.

I claim:

l. In a device of the class described, a despatch tube, connections for supplying compressed air thereto, a valve for controlling the supply of compressed air, a piston having a port, a connection between said piston and said valve, a working chamber for containing cornpressed air to ope 'ate said piston, and means comprising a hollow push rod open at one end' and having a port of greater area than said piston port for releasing the air pressure on one side of said piston to enable the compressed air on the other side thereof to operate said piston and unseat said valve.

2. In a device of the class described, a despatch tube, connections for supplying cornpressed air thereto, a valve for controlling the supply of compressed air having a hollow stem open at both ends, a piston secured to said stem and `having a port to permit the passage of air therethrough, a working chamber for containing compressed air to operate said piston, a hollow push rod slidably mounted in said valve stein and normally projecting from the end thereoft a valve on said rod, a valve seat on which said valve is normally seated, a port in said rod between said rod valve and its valve seat of greater area than said piston port, means to operate said rod to unseat said rod valve to permit the air on on'side of said piston to flow through said rod and enable the air on the other side thereof to operate said piston and unseat said air control valve.

1n a device of the class described, a despatch tube having a carrier intake port, a cover for said port, connections for supplying compressed air to said tube, a valve for controlling the supply of compressed air, a piston having a port, a connection between said piston and said valve, a working chamber for containing compressed air to operate said piston, means for releasing the air pressure on one side of said piston to enable the compressed air on the other side thereof to operate said piston and unseat said valve, said releasing means comprising a hollow' push rod in said working chamber and normally projecting therefrom, and having a. port of greater area than said piston port and an open end, and an operating member common to both said cover and said push rod adapted to close said cover and depress said push rod.

l, in a device of the class described, a despatch tube having a carrier intake port, a cover for said port, connections for supplying compressed air to said tube, a valve for controlling the supply of compressed air, a piston having a port, a connection between said piston and said valve, a working chamber for containing compressed air to operate said piston, means for releasing the air pressure on one side of said piston to enable the compressed air on the other side thereof to operate said piston and unseatsaid valve, said releasing means comprising a hollow push rod in said working chamber and normally projecting therefrom` and having a portof greater area than said piston port and an open end, an operating member common to both said cover and said push rod adapted to close said cover and depress said push rod, and means to return said push rod to normal position.

5. In a device of the class described, a despatch tube having a carrier intake port, a cover for said port, connections for supplying compressed air to said tube, a valve for controlling the supply of compressed air having a hollow stem open at both ends, a piston secured to said stem and lia-ving a port, a working chamber for containing compressed air to operate said piston, a hollow push rod slidably mounted in said stem and normally projecting from t-he end thereof, a valve on said rod, a valve seat on which said rod valve is normally seated,

on one side of said piston to iiow throughY said port in said rod to enable the air on the other side thereof to operate said piston and unseat said air control valve.

6. 1n a ldevice of the class described, a

despatch tube having a carrier intake port, f

a cover for said port, connections for supplying compressed air to said tube, a valve for controlling the supply of compressed air having a hollow stem open at both ends, a piston secured to said stem and having a port, a working chamber for containing compressed air to operate said piston, a cap for said chamber, a hollow push rod slidably mounted in said stem and normally projecting from said cap, a valve on said rod, a valve seat on which said valve is normally seated, a port in said rod between said valve and said seat of greater area than said piston port, an operating member common to said cover and said push rod adapted to close said cover and depress said push rod to unseat said valve to permit the air on one side of said piston to flow through said port in said rod to' enable the air on the other side thereof to operate said piston and unseat said air control valve, and a spring surrounding said push rod and adapted to return it to normal position.

7. In a device of the class described, a casing, a despatch tube in said casing having a carrier intake port, a cover for said port, a compressed air operated air supply valve, means comprising a push rod for controlling the opening of said valve, an arm movably mounted on said casing, a lever connected with said cover, adapted to close said cover and thereafter to move said arm to operate said push rod.

8. In a device of the class described, a casing, a despatch tube in said casing having a carrier intakeport, a cover for said portpivoted on said casing, a compressed air operated air supply valve, means comprising a push rod for controlling the opening of said valve, an arm movably mounted on said casing, a lever pivoted on said cover, a yielding element between said lever and said cover, said lever adapted to close said cover and thereafter to move said arm to operate said push rod.

Signed by me at Boston, Massachusetts, this 23rd day of July, 1914.

ALEXANDER WATSON. TWitnesses CHARLES D. VOODBERRY, RICHARD W. HALL. Y

Copies of this patent may be obtained for ive cents each, by addressing the Commissioner of Patents, Washington, D. C. 

